Current methods for DNA sequencing often involve interrogation of many amplified DNA templates on the surface of a bead or slide. Polymerase incorporation of nucleotides can be measured by measuring fluorescence (e.g., Helicos, Illumina technologies) the generation of pyrophosphate (454 technology) or H+ ions (Ion torrent technology). While these methods are rapidly increasing in accuracy and throughput, sequencing technologies that could interrogate a single DNA molecule would obviate the need for DNA amplification of templates, and could potentially enable the detection of DNA modifications such as methylation.